Diddley Bow

Constructomaton has been wanting to build a diddley bow for ages.  Essentially, a diddley bow is a one-stringed lap-steel guitar, generally made out of household materials by financially-challenged blues/folk musicians.  Here's Jack White making one in about 10 seconds.  Looks easy, right?

I wanted mine to be a bit fancier than this, so spent a while tracking down the necessary materials.
A diddley bow is basically a length of wire stretched between two fixed points attached to a piece of wood, so you can pretty much use anything.

Most people seem to use glass bottles for the bridge (the bit the string goes over at the bottom of the diddley bow), and metal bolts, wooden dowels or just nails for the nut (the bit the string goes over at the top). 

Here's my parts list:

• Wood: 4cm x 7cm pine plank, 87cm long.  You can pretty much use any size piece of wood, of any kind, as long as it's strong enough not to break under string tension.  Hardwood would probably sound better than softwood, as it's denser, but I found mine in a pile of firewood and it sounds fine.
• Bottles: a larger one for the 'bridge', and a smaller one for the 'nut'.  I used a stubby ginger ale bottle for the bridge and a miniature whiskey bottle for the nut.
• Machine head:  to adjust the tension of the string.  I used one from an old guitar, but you could probably pick one up from a guitar shop or ebay.  
• String: any piece of metal wire will do, but I used a bass guitar string.  The thicker the wire/string you use, the more tension everything will be under, so watch out. 
• Pick-up:  to amplify the sound from the string.  I had an old P100 lying around.  You could make an acoustic diddley bow, but you'd need to add a resonator (like a cigar box) to make it loud enough to hear.
• Electrics:  you'll need to make a simple tone/volume circuit to control the output of the pick-up.  I used 2 x 500k potentiometers (one log (volume) one lin (tone)), a 1/4 inch guitar jack input, and a .047 capacitor.  I used a couple of chicken-feet knobs for the volume and tone controls.
• You'll also need some basic woodworking tools (chisels, saw, drill), wire cutters, a screwdriver and a soldering iron.

First I worked out where I wanted the two bottles for the bridge and nut to go.  It doesn't really matter how far apart they are (the scale length) but I replicated the scale length of my telecaster (25.5 inches), as it seemed like a good idea at the time.  So the centre of the ginger beer bottle is 25.5 inches apart from the whiskey bottle.  Using a chisel, I carved recesses in the wood to fit each bottle, so that they wouldn't move about once string tension was holding them in place (they're not glued in in case I want to change them if they break).

I also carved the top (nut) end of the wood so it'd be thin enough to fit the machine head through.  I drilled a hole at the other (bridge) end, reinforced it with a length of thin metal pipe (to stop the string cutting into the wood under tension) and glued a small metal washer on the underside to anchor the string.

 

 

I now had to hollow out a space in the side of the wood using a chisel, to house the electrics. I soldered my circuit together first and attached the pots to a small piece of wood so I knew how big the hole had to be.  I found a mustard powder tin that was the perfect size to house my pickup and punched holed in for the poles to poke through, then glued this to the wood, and drilled a hole for the wire to go through to the electrics compartment.

 

Now I just needed to add the bottles and the string:

      

Hooray - one finished diddley-bow!  It sounds pretty good - traditionally you play them with some sort of slide (I use my lap steel tone-bar) with your left hand, and hit the string using a stick in your right hand.  It's pretty good for playing bassy, low-fi slide, if ever you wanted to do such a thing.